A typical transmissive display may have a reduced contrast of an image due to ambient light in outdoor environment or under bright light. By comparison, a reflective display, which relies on an external light source to achieve the display effect, exhibits better display effect and contrast in outdoor or under bright light, and can reduce a considerable amount of power consumed during use of backlight, thus the reflective display is very suitable for use in portable electronic products. However, when the brightness of the ambient light source is insufficient, the contrast and the brightness of the reflective display will be greatly influenced. Therefore, a transflective display, if manufactured by using a transmissive technique in combination with an auxiliary backlight source, can simultaneously have advantages of both the transmissive display and the reflective display.
For the transflective liquid crystal display, a transmission region and a reflection region having a reflecting layer are provided in one pixel region at the same time. In relatively dark places, an image may be displayed by using the backlight source and the transmission region in the pixel region; in relatively bright places, an image may be displayed by using the ambient light (not the backlight source) and the reflection region in the pixel region. Liquid crystal matrices are generally categorized into active liquid crystal matrices and passive liquid crystal matrices. Changing voltage by a passive element to control orientation of liquid crystal molecules is called as passive drive, and a passive liquid crystal matrix is utilized. Changing voltage by an active element is called as active drive. A passive element commonly used for driving liquid crystal is for example a capacitor, and an active element is for example a transistor. Thus, the transflective liquid crystal display is suitable not only for the passive drive, but also for an active drive technique using an amorphous silicon (a-Si) Thin Film Transistor (hereinafter referred to as TFT), a Low Temperature Polysilicon (LTPS) TFT, or the like. Since the transflective liquid crystal display does not need to use a backlight source for a long time, it has an advantage of reducing the power consumption.
At present, an Advanced super Dimension Switch (hereinafter referred to as ADS) type liquid crystal display, due to the advantages of wide view angle, high transmissivity, low color difference and the like, has been widely applied. For an ADS type liquid crystal display, a multidimensional electric field is formed by electric fields generated on the edges of slit electrodes in a same plane and electric fields generated between a slit electrode layer and a plate electrode layer, so that the liquid crystal molecules in all orientations between and right above the slit electrodes in a liquid crystal cell can be rotated, thereby improving the working efficiency of the liquid crystals and increasing the light transmittance.
A TFT array substrate in the ADS type liquid crystal display panel generally includes a substrate and a plurality of pixel units arranged in an array on the substrate. Each pixel unit includes a TFT electrically connected to a gate line and a data line on the substrate, respectively, and a pixel electrode electrically connected to a source of the TFT through a via hole. Specifically, the pixel electrode is a slit electrode having a certain angle of inclination. The TFT array substrate further includes a common electrode which forms an electric field with the pixel electrode, and degree of rotation of the liquid crystal molecules is controlled by changing intensity of the electric field formed between the pixel electrode and the common electrode. The ADS type liquid crystal display has the advantages of high contrast, wide view angle, high definition, etc. Thus, it is very important to develop a transflective ADS type liquid crystal display.
FIG. 1 shows a transflective ADS type liquid crystal display of the prior art. As shown in FIG. 1, a liquid crystal display panel of the display includes an upper polarizing layer 1, an upper substrate 2, a lower substrate 4, a lower polarizing layer 5, and a liquid crystal layer 3 provided between the upper substrate 2 and the lower substrate 4. Each pixel unit of the liquid crystal display panel may be divided into a transmission region T and a reflection region R. When preparing the liquid crystal display panel by using an existing technique, due to different display modes of the transmission region T and the reflection region R (that is, the transmission region T is in a normally black display mode while the reflection region R is in a normally white display mode), a technique such as an in-cell retarder, a multi-domain structure or the like is required to be employed for the ADS type liquid crystal display, resulting in complex process and large difficulty. Moreover, due to reasons such as rubbing and touching of the upper substrate or the like, the static electricity generated on the upper substrate may cause a defective electric field inside the transflective ADS type liquid crystal display, resulting in defective liquid crystal orientation.
In order to solve the above problems, the present invention makes some beneficial improvements.